Difficult to say what is going on in Belgium & Netherlands with the death of young riders. Is it simply they get reported and there is half a dozen young cyclists deaths each decade in all countries too, but we don't hear about them in cycling press perhaps? Can't believe with social media today, this wouldn't hit most cycling press in each country. UK figures in young people (14-35) shows 12 deaths per week from undiagnosed heart conditions. Niels De Vriendt I read, was said to have had a cardiac screening 2 weeks ago, but what tests I don't know. There are generic tests like ECG & Echo, then there are more involved exercise-based ECG & Echo that can find conditions not found in more basic tests and several more specific tests too.